BTW I did NOT come up with this; I took it from another of the threads on this subject. I am about to buy either a 5D3 or a 6D, and I would like to know what others think about this beefy AF beam as a possible solution/aid to AF on 5D3??

I am seeing this concern from 5D3 shoppers often now. The 5D3 I purchased would not AF in low light well at all. It sucked. I exchanged it for another new copy from the dealer and the 2nd body worked much better. Some 5D3 owners see nothing to complain about, others can't even use their 5D3 bodies in low light. The 5D3 I now have is better than my classic 5D in low light without AF Beam. Perhaps not as 'better' as I would have expected for $3K however. I now have a 6D to compare it with and will report back on this forum later about that but so far, the 6D does AF better in low light with the few things I've quickly tried to AF Lock on in low light.

I have a YN 622 unit and its AF Beam does help but keep in mind that if you just want the AF Beam, you have to disable the flash in the menu or it will underexpose since the camera thinks a flash is going to fire, even if a flash isn't mounted to the 622 unit.

Personally, I didn't spend $3K so I could add workarounds to the camera to achieve optimum low light AF. With 7 years of tech progress since my 5D and 4 years of tech progress since the 5D-II, I expected better low light AF performance than I am seeing from the 5D3. There is definitely a lot of marketing hype going on with regard to low light AF on the 5D3.

Keep in mind that I am not referring to any of the other spectacular things the 5D3 is great at, just low light performance. (Because that is what I needed and waited for.)

I have suggested to others that they RENT the 5D3 and the 6D and see what works for them before making a big investment. If after using both bodies they are still not sure, rent the 5D-II and see if it would work for your needs and get a great deal on that. Personally, I think the 6D will end up working fine for me since I don't necc require the super-badass 61 pt AF or many of the other extra features that it excels at. The 6D works great, ignore most of the negative comments about it because if you read the comments from ACTUAL USERS, they love the camera. In fact, I think many 5D3 owners would love the 6D as a backup to get the best of both worlds. I will probably sell my 5D3 but having both does have some appeal.

I exchanged it for another new copy from the dealer and the 2nd body worked much better.

That's interesting. Looks Canon has QC problem for its 5D3.My 5D3 works fine for low light. However, I still like to have a AF assist bean. Dose anyone know if there is a small device for AF assist bean only.

the problem i have with the 622c on the 6d is that it doesnt sit correctly on the hot shoe, the beam is way above the top foucus point. i have to tilt the 622c down so the center foucus points can track the beam. it was too slow for my taste to focus for me with af assist on, i turned it off and everything is fine for me. i am happy the 622c works cause the yongnuo st-e2 didn't work on the 6d.

I exchanged it for another new copy from the dealer and the 2nd body worked much better.

That's interesting. Looks Canon has QC problem for its 5D3.My 5D3 works fine for low light. However, I still like to have a AF assist bean. Dose anyone know if there is a small device for AF assist bean only.

I found that my Yongnuo ST-E2 knock off works brilliantly as AF assist only (it does not work with actuall flash on the 5Dmk3 as everything seems out of sync but for AF assist it works perfectly this is tested in a pitch black theater room aiming at a pure white theater projector screen and AF is instant below is a markup of the AF points that work using the ST-E2 copy

I exchanged it for another new copy from the dealer and the 2nd body worked much better.

That's interesting. Looks Canon has QC problem for its 5D3.My 5D3 works fine for low light. However, I still like to have a AF assist bean. Dose anyone know if there is a small device for AF assist bean only.

Yeah, no kidding. I had my fingers crossed on the replacement. I was doubtful but I was trying to be positive since I knew other photographers that didn't seem to have any trouble at all. If they had experienced the problems I was seeing with the first body, there was no way they could say that. So I really prayed that the replacement would work better and so far it is working better. What a PITA. Many hours of my life I'd like to have back. Sigh.

crasher8

This has all been a very interesting read. Once again it seems as when an inexpensive product comes along and might just satisfy your needs from an ad or a review, it once again is too good to be true and it's valuable experiences like those shared here to confirm that. Now if I could apply this to the Vello Freewave Fusion transceivers I'd know whether to go down that road or not. Anyone care to share why I should or should not go with them to fire a pair of off camera 430ex's from a 5D3?

Logged

AdamJ

The hot shoe mounts on the 622s are not quite perpendicular - enough to be visually discernible. However, there are a few degrees of wiggle-room available in the hot shoe, allowing the AF beams on two of my 622s to be centred laterally. The beams on the other two remain offset slightly to the right.

The beams on all four units aim above the central focus point, due to the vertical offset of the 622 relative to the lens. All four of my units show the same amount of offset. At subject distances below about 4ft, the offset is such that the outer portion of the beam misses the central AF box. Above that, the offset diminishes so that at 5ft, the central AF box is partially covered and at about 7ft, it's fully covered.

Obviously, focal length determines how big the beam is in relation to the image area so the longer the focal length, the more surrounding AF points are covered.

Dave_NYC

So I've been testing my 622c with my 5D Mk III, and two lenses - Tamron 24-70mm f/2.8 VC, and my nifty fifty, dark room with a full press firing a flash (but no pre - the only light in the room is the 622c AF assist light), but trying a combination of full press, and half press focus lock confirmation then full press.

Both claim to lock focus in a second or less when using the 622c (i.e. they beep). Only the nifty is actually nailing focus consistently though. And the Tamron ONLY struggles when I am using the AF assist light from the 622c on top of the camera, and only when the subject or point of focus is several feet or more away. It tends to backfocus a lot (by several inches), though it apparently got bored and decided to shift to front focus for a bit of variety a couple of times. Within a few feet of subject, it nails focus every time on just the 622c AF assist light.

Ironically, my 60D with the same lens and 622c nails the focus every single time. It's quick, it's accurate - very close to the same as shooting with either body with continuous lights on (with continuous lights on, the back/front focus issue on the Tamron simply doesn't appear).

I don't know how the 622c/5d Mk iii lens is going to react to different lenses is the bottom line. I know it doesn't play well with my Tammy when I absolutely have to have the AF assist to focus at distances of several feet or more (makes me wonder how the 70 - 200 II would be with this). Otherwise, I can shoot several feet in front of me with no problems. Or I can put it on my 60D on the few occasions where I'm in that dark of an environment and I need to be able to back up without going wide.

Good thing is a little 622c doesn't cost that much. I wonder how the Canon 24 - 70 II 2.8 would do with it on a 5D Mk III body, if anyone is able to test I'd be very curious to hear what your experience was.